1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

use mesh::Mesh;
use mesh::Id;

pub struct FaceIterator<'a> {
    index: usize,
    mesh: &'a Mesh,
}

impl<'a> Iterator for FaceIterator<'a> {
    type Item = Id;

    fn next(&mut self) -> Option<Id> {
        while self.index < self.mesh.faces.len() {
            let face = &self.mesh.faces[self.index];
            self.index += 1;
            if face.alive {
                return Some(face.id)
            }
        }
        None
    }
}

impl<'a> FaceIterator<'a> {
    pub fn new(mesh: &'a Mesh) -> FaceIterator<'a> {
        FaceIterator {
            index: 0,
            mesh: mesh,
        }
    }

    pub fn into_vec(self) -> Vec<Id> {
        let mut vec = Vec::new();
        for id in self {
            vec.push(id);
        }
        vec
    }
}

pub struct FaceHalfedgeIterator<'a> {
    stop_id: Id,
    current_id: Id,
    index: usize,
    mesh: &'a Mesh,
}

impl<'a> Iterator for FaceHalfedgeIterator<'a> {
    type Item = Id;

    fn next(&mut self) -> Option<Id> {
        let id = self.current_id;
        if self.mesh.halfedge_start_vertex(id).is_none() {
            return None;
        }
        self.current_id = self.mesh.halfedge(self.current_id).unwrap().next;
        if id == self.stop_id && self.index > 0 {
            return None;
        }
        self.index += 1;
        Some(id)
    }
}

impl<'a> FaceHalfedgeIterator<'a> {
    pub fn new(mesh: &'a Mesh, start_id: Id) -> FaceHalfedgeIterator<'a> {
        FaceHalfedgeIterator {
            stop_id: start_id,
            current_id: start_id,
            index: 0,
            mesh: mesh,
        }
    }

    pub fn into_vec(self) -> Vec<Id> {
        let mut vec = Vec::new();
        for id in self {
            vec.push(id);
        }
        vec
    }
}

pub struct VertexHalfedgeIterator<'a> {
    stop_id: Id,
    current_id: Id,
    index: usize,
    mesh: &'a Mesh,
}

impl<'a> Iterator for VertexHalfedgeIterator<'a> {
    type Item = Id;

    fn next(&mut self) -> Option<Id> {
        let id = self.current_id;
        if self.mesh.halfedge_start_vertex(id).is_none() {
            return None;
        }
        self.current_id = {
            if 0 == self.index % 2 {
                self.mesh.halfedge(self.current_id).unwrap().opposite
            } else {
                self.mesh.halfedge(self.current_id).unwrap().next
            }
        };
        if id == self.stop_id && self.index > 0 {
            return None;
        }
        self.index += 1;
        Some(id)
    }
}

impl<'a> VertexHalfedgeIterator<'a> {
    pub fn new(mesh: &'a Mesh, start_id: Id) -> VertexHalfedgeIterator<'a> {
        VertexHalfedgeIterator {
            stop_id: start_id,
            current_id: start_id,
            index: 0,
            mesh: mesh,
        }
    }

    pub fn into_vec(self) -> Vec<Id> {
        let mut vec = Vec::new();
        for id in self {
            vec.push(id);
        }
        vec
    }
}